Acidic exposures

Acidic exposures

by Postcourier

8th February 2006

COMMUNITIES down the riverine system of the Fly River will be exposed to a major acid disaster if appropriate measures are not taken to address the problem. The impact will be even bigger if the area was exposed to another El Nino or heavy rain or flooding after the mine life.

Acid rock drainage (ARD) from the Ok Tedi Mining Limited is posing problems in the Ok Tedi and Fly River systems in the Western Province. OTML managing director Keith Faulkner said yesterday that the ARD would pose a serious threat to the
riverine system after the mine closed in 2012.

But he said the company was working hard to ensure that the impacts were minimised and OTML had also started investigating options by mitigating sulphur and copper impacts. Mining Minister Sam Akoitai told the Post-Courier that the Government had requested the mining company to find a technical solution to address the impacts of ARD. He said there were studies underway by both the company and Government officials to find possible ways to reduce the problem.

Mr Faulkner told an environment briefing for non-government organisations yesterday that although the mining company made a massive profit of K1.3 billion last year, it was still faced with the severe environmental impacts, especially along the Fly River.

He said when OTML was still owned by BHPBilliton, options were investigated to address environmental problems and the only option was to close down the mine. The Government decided against closing the mine as it saw it was the major contributor to Government coffers. In 2004, the company's exports represented one quarter of PNG's total exports. ARD happens when naturally-occurring sulphide minerals such as pyrite (fool's gold) in the rock or waste materials from mining are exposed to air, water and oxidise to form an acidic water.

This oxidisation process also converts metals like copper, zinc and lead into more water-soluble forms - posing a risk to aquatic organisms in downstream waters. ARD is a natural process but it can be greatly increased by human activities such as farming, mining and road building where large areas of potentially acid-forming material are exposed to air. Mr Faulkner also said that this year the company had started the formal review of the community mine continuation agreements (CMCA) with affected communities with the aim of re-settling the balance of the mine's social, environmental and economic impacts.